Inbred maize line PH0B4

ABSTRACT

An inbred maize line, designated PH0B4, the plants and seeds of inbred maize line PH0B4, methods for producing a maize plant produced by crossing the inbred line PH0B4 with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH0B4 with another maize line or plant.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation in part of copending commonly owned Inbred MaizeLine PH0B4 filed Sep. 5, 1995 by Mark David Hoffbeck (Ser. No.08/524,016) abandoned.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto an inbred maize line designated PH0B4.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety or hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant.

Plants that have been self-pollinated and selected for type for manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twodifferent homozygous lines produces a uniform population of hybridplants that may be heterozygous for many gene loci. A cross of twoplants each heterozygous at a number of gene loci will produce apopulation of hybrid plants that differ genetically and will not beuniform.

Maize (zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

A reliable method of controlling male fertility in plants offers theopportunity for improved plant breeding. This is especially true fordevelopment of maize hybrids, which relies upon some sort of malesterility system. There are several options for controlling malefertility available to breeders, such as: manual or mechanicalemasculation (or detasseling), cytoplasmic male sterility, genetic malesterility, gametocides and the like.

Hybrid maize seed is typically produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twoinbred varieties of maize are planted in a field, and the pollen-bearingtassels are removed from one of the inbreds (female). Providing thatthere is sufficient isolation from sources of foreign maize pollen, theears of the detasseled inbred will be fertilized only from the otherinbred (male), and the resulting seed is therefore hybrid and will formhybrid plants.

The laborious, and occasionally unreliable, detasseling process can beavoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMSinbred are male sterile as a result of factors resulting from thecytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent inmaize plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile. Usually seedfrom detasseled fertile maize and CMS produced seed of the same hybridare blended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Theseand all patents referred to are incorporated by reference. In additionto these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. patentapplication Ser. No. 07/848,433, have developed a system of nuclear malesterility which includes: identifying a gene which is critical to malefertility; silencing this native gene which is critical to malefertility; removing the native promoter from the essential malefertility gene and replacing it with an inducible promoter; insertingthis genetically engineered gene back into the plant; and thus creatinga plant that is male sterile because the inducible promoter is not "on"resulting in the male fertility gene not being transcribed. Fertility isrestored by inducing, or turning "on", the promoter, which in turnallows the gene that confers male fertility to be transcribed.

There are many other methods of conferring genetic male sterility in theart, each with its own benefits and drawbacks. These methods use avariety of approaches such as delivering into the plant a gene encodinga cytotoxic substance associated with a male tissue specific promoter oran antisense system in which a gene critical to fertility is identifiedand an antisense to that gene is inserted in the plant (see:Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCTapplication PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach.

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. The development of maize hybrids requires, in general,the development of homozygous inbred lines, the crossing of these lines,and the evaluation of the crosses. Pedigree breeding and recurrentselection breeding methods are used to develop inbred lines frombreeding populations. Breeding programs combine the genetic backgroundsfrom two or more inbred lines or various other broad-based sources intobreeding pools from which new inbred lines are developed by selfing andselection of desired phenotypes. The new inbreds are crossed with otherinbred lines and the hybrids from these crosses are evaluated todetermine which of those have commercial potential.

Pedigree breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded in the breeding population. In the pedigree method, superiorplants are selfed and selected in successive generations. In thesucceeding generations the heterozygous condition gives way tohomogeneous lines as a result of self-pollination and selection.Typically in the pedigree method of breeding five or more generations ofselfing and selection is practiced: F₁ →F₂ ; F₂ →F₃ ; F₃ →F₄ ; F₄ →F₅,etc.

Recurrent selection breeding, backcrossing for example, can be used toimprove an inbred line. Backcrossing can be used to transfer a specificdesirable trait from one inbred or source to an inbred that lacks thattrait. This can be accomplished, for example, by first crossing asuperior inbred (recurrent parent) to a donor inbred (non-recurrentparent), that carries the appropriate gene(s) for the trait in question.The progeny of this cross is then mated back to the superior recurrentparent followed by selection in the resultant progeny for the desiredtrait to be transferred from the non-recurrent parent. After five ormore backcross generations with selection for the desired trait, theprogeny will be heterozygous for loci controlling the characteristicbeing transferred, but will be like the superior parent for most oralmost all other genes. The last backcross generation is then selfed togive pure breeding progeny for the gene(s) being transferred.

A single cross hybrid maize variety is the cross of two inbred lines,each of which has a genotype that complements the genotype of the other.The hybrid progeny of the first generation is designated F₁. In thedevelopment of hybrids only the F₁ hybrid plants are sought. PreferredF₁ hybrids are more vigorous than their inbred parents. This hybridvigor, or heterosis, can be manifested in many polygenic traits,including increased vegetative growth and increased yield.

The development of a hybrid maize variety involves three steps: (1) theselection of plants from various germplasm pools for initial breedingcrosses; (2) the selfing of the selected plants from the breedingcrosses for several generations to produce a series of inbred lines,which, although different from each other, breed true and are highlyuniform; and (3) crossing the selected inbred lines with differentinbred lines to produce the hybrid progeny (F₁). During the inbreedingprocess in maize, the vigor of the lines decreases. Vigor is restoredwhen two different inbred lines are crossed to produce the hybridprogeny (F₁). An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between a definedpair of inbreds will always be the same. Once the inbreds that give asuperior hybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F₁ progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁hybrids is lost in the next generation (F₂). Consequently, seed fromhybrid varieties is not used for planting stock.

Maize is an important and valuable field crop. Thus, a continuing goalof plant breeders is to develop high-yielding maize hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility of the crop to environmentalstresses. To accomplish this goal, the maize breeder must select anddevelop superior inbred parental lines for producing hybrids. Thisrequires identification and selection of genetically unique individualsthat occur in a segregating population. The segregating population isthe result of a combination of crossover events plus the independentassortment of specific combinations of alleles at many gene loci thatresults in specific genotypes. Based on the number of segregating genes,the frequency of occurrence of an individual with a specific genotype isless than 1 in 10,000. Thus, even if the entire genotype of the parentshas been characterized and the desired genotype is known, only a few ifany individuals having the desired genotype may be found in a large F₂or S₀ population. Typically, however, the genotype of neither theparents nor the desired genotype is known in any detail.

In addition to the preceding problem, it is not known how the genotypewill react with the environment. This genotype by environmentinteraction is an important, yet unpredictable, factor in plantbreeding. A breeder of ordinary skill in the art cannot predict thegenotype, how that genotype will interact with various environments orthe resulting phenotypes of the developing lines, except perhaps in avery broad and general fashion. A breeder of ordinary skill in the artwould also be unable to recreate the same line twice from the very sameoriginal parents as the breeder is unable to direct how the genomescombine or how they will interact with the environmental conditions.This unpredictability results in the expenditure of large amounts ofresearch resources in the development of a superior new maize inbredline.

Pioneer research station staff propose about 400 to 500 new inbreds eachyear from over 2,000,000 pollinations. Of those proposed new inbreds,less than 50 and more commonly less than 30 are actually selected forcommercial use.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line,designated PH0B4. This invention thus relates to the seeds of inbredmaize line PH0B4, to the plants of inbred maize line PH0B4, and tomethods for producing a maize plant produced by crossing the inbred linePH0B4 with itself or another maize line. This invention further relatesto hybrid maize seeds and plants produced by crossing the inbred linePH0B4 with another maize line.

DEFINITIONS

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. NOTE: ABS is in absolute termsand % MN is percent of the mean for the experiments in which the inbredor hybrid was grown. These designators will follow the descriptors todenote how the values are to be interpreted. Below are the descriptorsused in the data tables included herein.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9visual rating indicating the resistance to Anthracnose Stalk Rot. Ahigher score indicates a higher resistance.

BAR PLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Yield of the grain at harvest in bushelsper acre adjusted to 15.5% moisture.

CLD TST=COLD TEST. The percent of plants that germinate under cold testconditions.

CLN=CORN LETHAL NECROSIS. Synergistic interaction of maize chloroticmottle virus (MCMV) in combination with either maize dwarf mosaic virus(MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1 to 9 visualrating indicating the resistance to Corn Lethal Necrosis. A higher scoreindicates a higher resistance.

COM RST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicatingthe resistance to Common Rust. A higher score indicates a higherresistance.

D/D=DRYDOWN. This represents the relative rate at which a hybrid willreach acceptable harvest moisture compared to other hybrids on a 1-9rating scale. A high score indicates a hybrid that dries relatively fastwhile a low score indicates a hybrid that dries slowly.

DIP ERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance.

DRP EAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest.

DIT=DROUGHT TOLERANCE. This represents a 1-9 rating for droughttolerance, and is based on data obtained under stress conditions. A highscore indicates good drought tolerance and a low score indicates poordrought tolerance.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured in inches.

EAR MLD=General Ear Mold. Visual rating (1-9 score) where a "1" is verysusceptible and a "9" is very resistant. This is based on overall ratingfor ear mold of mature ears without determining the specific moldorganism, and may not be predictive for a specific ear mold.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

ECB 1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinianubilalis). A 1 to 9 visual rating indicating the resistance topreflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance.

ECB 21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk.

ECB 2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1to 9 visual rating indicating post flowering degree of stalk breakageand other evidence of feeding by European Corn Borer, Second Generation.A higher score indicates a higher resistance.

ECB DPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Droppedears due to European Corn Borer. Percentage of plants that did not dropears under second generation corn borer infestation.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on perplot basis for the inbred or hybrid.

EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9visual rating indicating the resistance to Eye Spot. A higher scoreindicates a higher resistance.

FUS ERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1 to 9 visual rating indicating the resistance toFusarium ear rot. A higher score indicates a higher resistance.

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, whichassumes that maize growth occurs in the temperature range 50° F.-86° F.and that temperatures outside this range slow down growth; the maximumdaily heat unit accumulation is 36 and the minimum daily heat unitaccumulation is 0. The seasonal accumulation of GDU is a major factor indetermining maturity zones.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GIB ERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9visual rating indicating the resistance to Gibberella Ear Rot. A higherscore indicates a higher resistance.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual ratingindicating the resistance to Gray Leaf Spot. A higher score indicates ahigher resistance.

GOS WLT=Goss' Wilt (Corynebacterium nebraskense). A 1 to 9 visual ratingindicating the resistance to Goss' Wilt. A higher score indicates ahigher resistance.

GRN APP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plantdensities on 1-9 relative rating system with a higher number indicatingthe hybrid responds well to high plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to increased plant density.

HC BLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporiumcarbonum). A 1 to 9 visual rating indicating the resistance toHelminthosporium infection. A higher score indicates a higherresistance.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates thepercentage of plants not infected.

INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acreassuming drying costs of two cents per point above 15.5 percent harvestmoisture and current market price per bushel.

KSZ DCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated asthe sum of discarded tip kernels and extra large kernels.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybridon per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety #1over variety #2.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1-9 relative system with a higher number indicating thehybrid responds well to low plant densities for yield relative to otherhybrids. A 1, 5, and 9 would represent very poor, average, and very goodyield response, respectively, to low plant density.

MDM CPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus andMCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating theresistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

MST ADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 overvariety #2 as calculated by: MOISTURE of variety #2--MOISTURE of variety#1=MOISTURE ADVANTAGE of variety #1.

NLF BLT=Northern Leaf Blight (Helminthosporium turcicum or Exserohilumturcicum). A 1 to 9 visual rating indicating the resistance to NorthernLeaf Blight. A higher score indicates a higher resistance.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in inches.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POL WT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

It should be understood that the inbred can, through routinemanipulation of cytoplasmic or other factors, be produced in amale-sterile form. Such embodiments are also contemplated within thescope of the present claims.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage ofvariety #1 over variety #2 as calculated by PLANT POPULATION of variety#2--PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety#1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and is also referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

PRM SHD=A relative measure of the growing degree units (GDU) required toreach 50% pollen shed. Relative values are predicted values from thelinear regression of observed GDU's on relative maturity of commercialchecks.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that donot root lodge; plants that lean from the vertical axis at anapproximately 30° angle or greater would be counted as root lodged.

RTL ADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1over variety #2.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A maizebreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

SLF BLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance.

SOU RST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance.

STA GRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STD ADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STK CNT.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plantsper plot.

STK LDG=STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

STW WLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at thetime of flowering. A 1 would indicate a very high level of blasting attime of flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data is given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain inpounds for a given volume (bushel) adjusted for 15.5 percent moisture.

TSW ADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1over variety #2.

WIN M %=PERCENT MOISTURE WINS.

WIN Y %=PERCENT YIELD WINS.

YLD=YIELD. It is the same as BU ACR ABS.

YLD ADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety#2 as calculated by: YIELD of variety #1--YIELD variety #2 =yieldadvantage of variety #1.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Inbred maize lines need to be highly homogeneous,homozygous and reproducible to be useful as parents of commercialhybrids. There are many analytical methods available to determine thehomozygotic and phenotypic stability of these inbred lines.

The oldest and most traditional method of analysis is the observation ofphenotypic traits. The data is usually collected in field experimentsover the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; amongthese are Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), and Simple SequenceRepeats (SSRs) which are also referred to as Microsatellites.

The most widely used of these laboratory techniques are IsozymeElectrophoresis and RFLPs as discussed in Lee, M., "Inbred Lines ofMaize and Their Molecular Markers," The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated hereinby reference. Isozyme Electrophoresis is a useful tool in determininggenetic composition, although it has relatively low number of availablemarkers and the low number of allelic variants among maize inbreds.RFLPs have the advantage of revealing an exceptionally high degree ofallelic variation in maize and the number of available markers is almostlimitless.

Maize RFLP linkage maps have been rapidly constructed and widelyimplemented in genetic studies. One such study is described inBoppenmaier, et al., "Comparisons among strains of inbreds for RFLPs",Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, is incorporatedherein by reference. This study used 101 RFLP markers to analyze thepatterns of 2 to 3 different deposits each of five different inbredlines. The inbred lines had been selfed from 9 to 12 times before beingadopted into 2 to 3 different breeding programs. It was results fromthese 2 to 3 different breeding programs that supplied the differentdeposits for analysis. These five lines were maintained in the separatebreeding programs by selfing or sibbing and rogueing off-type plants foran additional one to eight generations. After the RFLP analysis wascompleted, it was determined the five lines showed 0-2% residualheterozygosity. Although this was a relatively small study, it can beseen using RFLPs that the lines had been highly homozygous prior to theseparate strain maintenance.

Inbred maize line PH0B4 is a yellow, dent maize inbred that is bestsuited as a female in crosses for producing first generation F₁ maizehybrids. Inbred maize line PH0B4 is best adapted to the Central CornBelt of the United States and can be used to produce hybrids fromapproximately 112 relative maturity based on the Comparative RelativeMaturity Rating System for harvest moisture of grain. Inbred maize linePH0B4, as an inbred per se, exhibits high yield, above average cold testresults, low discard seed size, excellent staygreen and poor early standcount. PH0B4 is unique as an inbred per se in that it has sun red in thetassel which can be confused with anther color segregation and it hashigh yield with low stand counts.

In hybrid combination, PH0B4 exhibits high yield, good seedling vigor,and good root lodging resistance. In addition, PH0B4 hybrids aresurprising as they tend to have below average staygreen whereas PH0B4,as an inbred per se, has above average staygreen.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows. The inbred has beenself-pollinated and ear-rowed a sufficient number of generations withcareful attention paid to uniformity of plant type to ensure thehomozygosity and phenotypic stability necessary to use in commercialproduction. The line has been increased both by hand and in isolatedfields with continued observation for uniformity. No variant traits havebeen observed or are expected in PH0B4.

Inbred maize line PH0B4, being substantially homozygous, can bereproduced by planting seeds of the line, growing the resulting maizeplants under self-pollinating or sib-pollinating conditions withadequate isolation, and harvesting the resulting seed, using techniquesfamiliar to the agricultural arts.

                  TABLE 1    ______________________________________    VARIETY DESCRIPTION INFORMATION    INBRED = PH0B4    Type: Dent    ______________________________________    A.   Maturity: Average cross maturity zones. Zone: 0         GDU Shed: 1420         GDU Silk: 1430         No. Reps: 21    B.   Tassel:         Anther Color: Yellow* and Red*         Glume Color: Red*    C.   Ear (Husked Ear Data Except When Stated Otherwise):         Silk Color Yellow*    D.   Cob:         Color: White*    E.   Diseases:         Gray Leaf Spot (C. zeae): Intermediate*    F.   Insects:         European Corn Borer-1 Leaf Damage (Pre-flowering): Susceptible         European Corn Borer-2 (Post-flowering): Intermediate         The above descriptions are based on a scale of 1-9, 1 being highly         susceptible, 9 being highly resistant.         S (Susceptible): Would generally represent a score of 1-3.         I (Intermediate): Would generally represent a score of 4-5.         R (Resistant): Would generally represent a score of 6-7.         H (Highly Resistant) Would generally represent a score of 8-9.         Highly resistant does not imply the inbred is immune.    ______________________________________     *In interpreting the foregoing color designations, reference may be had t     the Munsell Glossy Book of Color, a standard color reference.

Data for Items B, C, D, E, F, and G is based primarily on descriptioninformation from the maintaining station.

INDUSTRIAL APPLICABILITY

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein the first or second parent maize plant is an inbred maize plantof the line PH0B4. Further, both first and second parent maize plantscan come from the inbred maize line PH0B4. Thus, any such methods usingthe inbred maize line PH0B4 are part of this invention: selfing,backcrosses, hybrid production, crosses to populations, and the like.All plants produced using inbred maize line PH0B4 as a parent are withinthe scope of this invention. Advantageously, the inbred maize line isused in crosses with other, different, maize inbreds to produce firstgeneration (F₁) maize hybrid seeds and plants with superiorcharacteristics.

As used herein, the term plant includes plant cells, plant protoplasts,plant cell tissue cultures from which maize plants can be regenerated,plant calli, plant clumps, and plant cells that are intact in plants orparts of plants, such as embryos, pollen, ovules, flowers, kernels,ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk andthe like.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91 % regenerable callus that produced plants. In a furtherstudy in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions that enhance regenerability ofcallus of two inbred lines. Other published reports also indicated that"nontraditional" tissues are capable of producing somatic embryogenesisand plant regeneration. K. P. Rao, et al., Maize Genetics CooperationNewsletter, 60:64-65 (1986), refers to somatic embryogenesis from glumecallus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347(1987) indicates somatic embryogenesis from the tissue cultures of maizeleaf segments. Thus, it is clear from the literature that the state ofthe art is such that these methods of obtaining plants are, and were,"conventional" in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture of maize is described in European Patent Application,publication 160,390, incorporated herein by reference. Maize tissueculture procedures are also described in Green and Rhodes, "PlantRegeneration in Tissue Culture of Maize," Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Va. 1982, at367-372) and in Duncan, et al., "The Production of Callus Capable ofPlant Regeneration from Immature Embryos of Numerous Zea MaysGenotypes," 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce maize plants having the physiological and morphologicalcharacteristics of inbred line PH0B4.

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch inthe wet- milling industry and maize flour in the dry-milling industry.The industrial applications of maize starch and flour are based onfunctional properties, such as viscosity, film formation, adhesiveproperties, and ability to suspend particles. The maize starch and flourhave application in the paper and textile industries. Other industrialuses include applications in adhesives, building materials, foundrybinders, laundry starches, explosives, oil-well muds, and other miningapplications.

Plant parts other than the grain of maize are also used in industry: forexample, stalks and husks are made into paper and wallboard and cobs areused for fuel and to make charcoal.

The seed of inbred maize line PH0B4, the plant produced from the inbredseed, the hybrid maize plant produced from the crossing of the inbred,hybrid seed, and various parts of the hybrid maize plant can be utilizedfor human food, livestock feed, and as a raw material in industry.

PERFORMANCE EXAMPLES OF PH0B4

In the examples that follow, the traits and characteristics of inbredmaize line PH0B4 are presented as an inbred per se and in hybridcombination. The data collected on inbred maize line PH0B4 is presentedfor key characteristics and traits.

The results in Table 2A compare PH0B4 to PHW20. The inbred per seresults show PH0B4 is significantily higher yielding with significantlyhigher seedling vigor than PHW20. PH0B4 is taller with a significantlyhigher staygreen score than PHW20. PH0B4 also demonstratessignificantily higher resistance to Southern Leaf Blight and lowerresistance to Stewart's Wilt than PHW20.

The results in Table 2B compare PH0B4 to its parent PHP38. The inbredper se results show PH0B4 is significantily higher yielding for itsmaturity than PHP38. PH0B4 is taller with a higher staygreen score thanPHP38.

Table 2C compares the inbred per se results of PH0B4 and PHHB9, asimilarly adapted line. Although the results show PHHB9 is higheryielding than PH0B4, both inbreds are above average yielding. Inaddition PH0B4 exhibits significantly lower harvest moisture. PH0B4demonstrates significantly higher seedling vigor and is taller thanPHHB9.

Table 2D compares the inbred per se results of PH0B4 and PHAG6. Theresults show inbred PH0B4 is significantily higher yielding with asignificantly lower tiller count than PHAG6. In addition, PH0B4 hassignificantly higher staygreen value and seedling vigor than PHAG6.PH0B4 is taller with significantly larger tassel size than PHAG6.

The results of Table 3A compare PH0B4 to PHP38 when crossed to the sameinbred testers. The results show PH0B4 hybrids are somewhat higheryielding than PHP38 hybrids. The results show PH0B4 have significantlylower seedling vigor than PHP38 hybrids, however both are above average.Both PH0B4 hybrids and PHP38 hybrids have above average resistance tobrittle stalk. PH0B4 hybrids also show a significantly higher stay greenscore than PHP38 hybrids (although both scores are below average).

Table 3B compares the general combining ability results of PH0B4 andPHHB9 when crossed to the same inbred testers. The results show thatPH0B4 hybrids have a higher seedling vigor and higher resistance tobrittle snap than PHHB9 hybrids. PH0B4 hybrids are slightly loweryielding but have lower harvest moisture than PHHB9 hybrids.

Table 3C compares the general ability results of PH0B4 and PHAG6 whencrossed to the same inbred testers. The results show both PH0B4 andPHAG6 hybrids are high yielding. PH0B4 hybrids demonstrate significantlyhigher seedling vigor and significantly better grain appearance thanPHAG6 hybrids.

The results in Table 4A compare the specific combining ability of PH0B4and PHR55 when crossed to PH08A and PHP38 respectively. The results showthat the PH0B4 hybrids are higher yielding with significantly lowerharvest moisture than the PHR55 hybrid. The PH0B4 hybrid hassignificantly higher test weight, seedling vigor and early stand countthan the PHR55 hybrid. The PH0B4 hybrid demonstrates below average staygreen.

The results in Table 4B compare the specific combining ability of PH0B4and PHHB9 crossed to PH08A and PHBE2 respectively. The results show thatboth hybrids are high yielding but the PH0B4 hybrid has lower harvestmoisture and a significantly higher test weight than the PHHB9 hybrid.The PH0B4 hybrid has significantly higher seedling vigor and higher rootlodging resistance, stalk lodging resistance and superior grainappearance when compared to the PHHB9 hybrid.

The results in Table 4C compare PH0B4 and PHP38 crossed to PH08A andPHPP8 respectively. The results show that the PH0B4 hybrid issignificantly higher yielding with a significantly higher test weightthan the PHP38 hybrid. The PH0B4 hybrid demonstrates higher seedlingvigor, higher resistance to root lodging and a higher stay green score(although both are below average) than the PHP38 hybrid. Both hybridshave below average harvest moisture.

The results in Table 4D compare the specific combining ability of PH0B4and PHP38 crosses with PH08A and PHN46 respectively. As the tablesillustrate, the PH0B4 hybrid is higher yielding with significantlyhigher test weight than the PHP38 hybrid. Both hybrids have very goodseedling vigor. The PH0B4 hybrid has a higher resistance to root lodgingand lower stay green than the PHP38 hybrid.

The results in Table 4E compare PH0B4 and PHAG6 crossed to PH08A. Thespecific combining ability results show that the PH0B4 hybrid is higheryielding with significantly higher seedling vigor than the PHAG6 hybrid.The PH0B4 hybrid demonstrates superior stay green and higher resistanceto stalk lodging than the PHAG6 hybrid. The PH0B4 hybrid issignificantly taller than the PHAG6 hybrid.

                                      TABLE 2A    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT    VARIETY #1 = PH0B4    VARIETY #2 = PHW20    __________________________________________________________________________               BU BU     TST                            SDG                               EST TIL                                      GDU                                         GDU               ACR                  ACR MST                         WT VGR                               CNT LER                                      SHD                                         SLK               ABS                  % MN                      ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   82.1                  123 18.9                         58.5                            5.6                               34.3                                   1.4                                      145.4                                         147.8           2   52.7                  77  17.3                         56.3                            2.5                               29.6                                   2.4                                      144.5                                         148.7           LOCS               24 24  29 22 49 72  40 44 43           REPS               36 36  41 32 68 91  52 47 45           DIFF               29.4                  45  1.6                         2.2                            3.1                               4.7 1.0                                      0.9                                         0.8           PR > T               .000#                  .000#                      .000#                         .000#                            .000#                               .000#                                   .161                                      .342                                         .338    __________________________________________________________________________               POL                  TAS PLT                         EAR                            RT STA STK                                      BRT                                         GRN               SC SZ  HT HT LDG                               GRN LDG                                      STK                                         APP               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   4.2                  4.4 87.4                         32.2                            86.9                               5.4 93.4                                      93.2                                         5.8           2   4.5                  5.3 82.0                         33.4                            99.4                               2.6 90.0                                      97.6                                         4.9           LOCS               11 23  30 28 7  18  11 13 4           REPS               12 24  42 40 9  25  18 18 5           DIFF               0.3                  1.0 5.3                         1.2                            12.4                               2.8 3.4                                      4.4                                         0.9           PR > T               .694                  .007#                      .000#                         .341                            .312                               .000#                                   .407                                      .198                                         .480    __________________________________________________________________________               SCT                  EAR TEX                         EAR                            BAR                               DRP GLF                                      NLF                                         SLF               GRN                  SZ  EAR                         MLD                            PLT                               EAR SPT                                      BLT                                         BLT               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   6.8                  6.5 5.7                         6.6                            94.1                               100.0                                   3.4                                      3.3                                         6.9           2   6.1                  4.9 3.6                         6.1                            92.9                               98.6                                   3.1                                      3.1                                         2.7           LOCS               9  8   7  8  25 4   9  5  5           REPS               10 8   7  9  27 7   14 10 8           DIFF               0.7                  1.6 2.1                         0.5                            1.3                               1.4 0.3                                      0.2                                         4.2           PR > T               .316                  .010+                      .002#                         .563                            .430                               .146                                   .325                                      .648                                         .002#    __________________________________________________________________________               GOS                  STW ANT                         HD    MDM FUS                                      COM                                         ECB               WLT                  WLT ROT                         SMT                            CLN                               CPX ERS                                      RST                                         1LF               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.3                  4.3 3.4                         96.4                            4.5                               3.5 4.5                                      6.0                                         3.7           2   7.5                  6.1 2.6                         88.0                            2.5                               2.5 7.0                                      5.5                                         5.7           LOCS               2  4   4  1  1  2   3  1  3           REPS               4  6   7  2  2  4   6  2  3           DIFF               0.3                  1.9 0.8                         8.5                            2.0                               1.0 2.5                                      0.5                                         2.0           PR > T               .500                  .009#                      .215     .295                                   .138  .074*    __________________________________________________________________________               ECB               2SC               ABS    __________________________________________________________________________    TOTAL SUM           1   3.0           2   3.0           LOCS               1           REPS               1           DIFF               0.0           PR > T    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 2B    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT    VARIETY #1 = PH0B4    VARIETY #2 = PHP38    __________________________________________________________________________               BU BU     TST                            SDG                               EST TIL                                      GDU                                         GDU               ACR                  ACR MST                         WT VGR                               CNT LER                                      SHD                                         SLK               ABS                  % MN                      ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   79.2                  123 18.2                         58.5                            5.4                               31.6                                   1.6                                      145.9                                         148.2           2   61.8                  92  18.1                         58.4                            5.8                               33.5                                   1.3                                      147.9                                         149.0           LOCS               31 31  36 25 70 116 67 86 86           REPS               47 47  52 37 90 160 83 92 92           DIFF               17.5                  31  0.1                         0.1                            0.5                               1.9 0.3                                      1.9                                         0.7           PR > T               .000#                  .000#                      .489                         .566                            .010+                               .019+                                   .591                                      .000#                                         .111    __________________________________________________________________________               POL                  TAS PLT                         EAR                            RT STA STK                                      BRT                                         GRN               SC SZ  HT HT LDG                               GRN LDG                                      STK                                         APP               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   4.5                  4.6 87.7                         31.6                            90.1                               5.3 93.4                                      90.6                                         6.4           2   5.4                  5.1 80.1                         30.9                            92.1                               4.7 95.7                                      94.6                                         7.3           LOCS               14 42  39 35 10 28  17 16 7           REPS               16 44  52 48 13 38  28 21 10           DIFF               0.9                  0.5 7.7                         0.8                            2.0                               0.6 2.3                                      4.0                                         0.9           PR > T               .038+                  .000#                      .000#                         .243                            .788                               .180                                   .071*                                      .366                                         .077*    __________________________________________________________________________               SCT                  EAR TEX                         EAR                            BAR                               DRP GLF                                      NLF                                         SLF               GRN                  SZ  EAR                         MLD                            PLT                               EAR SPT                                      BLT                                         BLT               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.0                  6.6 5.6                         6.8                            94.7                               99.4                                   3.7                                      3.3                                         7.3           2   5.7                  5.0 5.5                         7.1                            91.7                               98.6                                   2.4                                      3.7                                         8.0           LOCS               12 12  10 12 37 7   12 6  3           REPS               13 12  11 13 39 12  17 11 6           DIFF               1.3                  1.6 0.1                         0.3                            2.9                               0.7 1.3                                      0.4                                         0.7           PR > T               .018+                  .000#                      .758                         .339                            .102                               .418                                   .001#                                      .093*                                         .184    __________________________________________________________________________               GOS                  STW ANT                         HD    MDM FUS                                      COM                                         ECB               WLT                  WLT ROT                         SMT                            CLN                               CPX ERS                                      RST                                         1LF               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.3                  4.4 3.5                         96.4                            4.5                               3.5 4.5                                      4.6                                         3.5           2   7.8                  4.5 3.7                         100.0                            4.5                               3.0 5.0                                      5.0                                         3.5           LOCS               2  5   3  1  1  2   3  4  6           REPS               3  7   5  2  2  4   6  7  6           DIFF               0.5                  0.1 0.2                         3.6                            0.0                               0.5 0.5                                      0.4                                         0.0           PR > T               .500                  .778                      .910     .500                                   .729                                      .671                                         .999    __________________________________________________________________________               ECB               2SC               ABS    __________________________________________________________________________    TOTAL SUM           1   4.0           2   5.0           LOCS               3           REPS               3           DIFF               1.0           PR > T               .225    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 2C    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT    VARIETY #1 = PH0B4    VARIETY #2 = PHHB9    __________________________________________________________________________               BU BU     TST                            SDG                               EST TIL                                      GDU                                         GDU               ACR                  ACR MST                         WT VGR                               CNT LER                                      SHD                                         SLK               ABS                  % MN                      ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   70.4                  123 18.0                         58.6                            5.6                               30.8                                   1.6                                      145.5                                         147.7           2   79.9                  137 20.4                         57.3                            4.6                               34.4                                   14.1                                      148.4                                         150.1           LOCS               17 17  17 13 50 80  41 69 68           REPS               23 23  23 17 61 107 50 75 73           DIFF               9.5                  13  2.5                         1.4                            1.0                               3.5 12.5                                      2.9                                         2.3           PR > T               .016+                  .204                      .000#                         .030+                            .000#                               .000#                                   .000#                                      .000#                                         .000#    __________________________________________________________________________               POL                  TAS PLT                         EAR                            RT STA STK                                      BRT                                         GRN               SC SZ  HT HT LDG                               GRN LDG                                      STK                                         APP               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   4.4                  4.6 89.4                         31.3                            87.3                               5.0 92.3                                      95.5                                         6.3           2   3.9                  3.3 84.7                         28.7                            99.6                               6.1 88.5                                      91.9                                         5.8           LOCS               14 38  30 27 8  20  6  10 6           REPS               15 40  39 36 11 24  11 13 8           DIFF               0.5                  1.3 4.7                         2.6                            12.3                               1.1 3.8                                      3.7                                         0.5           PR > T               .169                  .000#                      .000#                         .002#                            .274                               .036+                                   .323                                      .581                                         .695    __________________________________________________________________________               SCT                  EAR TEX                         EAR                            BAR                               DRP GLF                                      NLF                                         SLF               GRN                  SZ  EAR                         MLD                            PLT                               EAR SPT                                      BLT                                         BLT               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.2                  6.7 5.6                         6.8                            95.0                               98.5                                   3.6                                      3.3                                         6.8           2   7.3                  6.9 6.3                         6.9                            97.0                               100.0                                   4.7                                      4.4                                         6.3           LOCS               9  9   9  9  20 3   9  5  5           REPS               10 9   10 10 20 5   15 10 10           DIFF               0.1                  0.2 0.8                         0.1                            2.1                               1.5 1.1                                      1.1                                         0.5           PR > T               .824                  .347                      .088*                         .760                            .169                               .184                                   .067*                                      .029+                                         .394    __________________________________________________________________________               GOS                  STW ANT                         HD    MDM FUS                                      COM                                         ECB               WLT                  WLT ROT                         SMT                            CLN                               CPX ERS                                      RST                                         1LF               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.3                  4.3 3.3                         96.4                            4.5                               3.5 4.5                                      4.6                                         3.6           2   6.8                  5.3 3 3                         100.0                            5.5                               3.0 6.8                                      5.2                                         3.6           LOCS               2  4   4  1  1  2   3  4  5           REPS               4  6   8  2  2  4   6  7  5           DIFF               0.5                  1.0 0.0                         3.6                            1.0                               0.5 2.3                                      0.5                                         0.0           PR > T               .705                  .066*                      .999     .500                                   .073*                                      .418                                         .999    __________________________________________________________________________               ECB               2SC               ABS    __________________________________________________________________________    TOTAL SUM           1   4.5           2   5.5           LOCS               2           REPS               2           DIFF               1.0           PR > T               .500    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 2D    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT    VARIETY #1 = PH0B4    VARIETY #2 = PHAG6    __________________________________________________________________________               BU BU     TST                            SDG                               EST TIL                                      GDU                                         GDU               ACR                  ACR MST                         WT VGR                               CNT LER                                      SHD                                         SLK               ABS                  % MN                      ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   84.1                  126 18.7                         58.1                            5.3                               31.6                                   1.5                                      145.8                                         148.3           2   75.1                  105 18.5                         58.1                            4.9                               33.4                                   7.6                                      148.0                                         150.9           LOCS               27 27  31 21 70 115 70 92 90           REPS               43 43  47 33 89 158 86 99 96           DIFF               9.0                  21  0.2                         0.0                            0.4                               1.8 6.1                                      2.2                                         2.6           PR > T               .013+                  .019+                      .386                         .999                            .034+                               .032+                                   .000#                                      .000#                                         .000#    __________________________________________________________________________               POL                  TAS PLT                         EAR                            RT STA STK                                      BRT                                         GRN               SC SZ  HT HT LDG                               GRN LDG                                      STK                                         APP               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   4.3                  4.6 88.0                         31.9                            98.1                               5.5 93.0                                      90.6                                         7.3           2   3.6                  3.6 77.9                         32.6                            93.9                               4.4 93.2                                      93.7                                         7.3           LOCS               15 42  39 35 9  26  16 16 4           REPS               17 44  53 49 13 36  27 21 7           DIFF               0.7                  1.0 10.1                         0.8                            4.2                               1.1 0.2                                      3.1                                         0.0           PR > T               .019+                  .000#                      .000#                         .275                            .136                               .017+                                   .905                                      .507                                         .999    __________________________________________________________________________               SCT                  EAR TEX                         EAR                            BAR                               DRP GLF                                      NLF                                         SLF               GRN                  SZ  EAR                         MLD                            PLT                               EAR SPT                                      BLT                                         BLT               ABS                  ABS ABS                         ABS                            ABS                               ABS ABS                                      ABS                                         ABS    __________________________________________________________________________    TOTAL SUM           1   7.0                  6.6 5.6                         6.8                            96.0                               99.4                                   3.7                                      3.6                                         6.8           2   5.9                  5.1 4.5                         6.3                            95.4                               99.0                                   2.7                                      3.5                                         4.7           LOCS               12 12  10 12 35 7   13 8  6           REPS               13 12  11 13 37 12  19 13 11           DIFF               1.1                  1.5 1.1                         0.6                            0.6                               0.4 1.0                                      0.1                                         2.2           PR > T               .003#                  .000#                      .032+                         .189                            .413                               .474                                   .019+                                      .857                                         .012+    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 3A    __________________________________________________________________________    Average Inbred By Tester Performance Comparing PH0B4 To PHP38 Crossed    To The Same Inbred Testers And Grown In The Same Experiments.    __________________________________________________________________________               SEL     BU  BU  PRM     TST SDG EST GDU               IND PRM ACR ACR SHD MST WT  VGR CNT SHD               % MN                   ABS ABS % MN                               ABS % MN                                       ABS % MN                                               % MN                                                   % MN    __________________________________________________________________________    TOTAL SUM           REPS               16  55  249 249 62  255 185 123 179 131           LOCS               16  55  174 174 62  178 128 82  118 75           PH0B4               103 110 144 101 112 99  56  104 93  100           PHP38               105 110 142 100 112 99  56  110 100 100           DIFF               1   0   2   2   G   0   0   6   7   0           PR > T               0.53                   0.99                       0.12                           0.07                               0.99                                   0.99                                       0.99                                           0.01                                               0.00                                                   0.99    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN STW               SLK CNT HT  HT  LDG GRN LDG STK APP WLT               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN                                                   ABS    __________________________________________________________________________    TOTAL SUM           REPS               87  324 181 179 69  62  237 8   13  1           LOCS               50  214 116 115 48  44  156 8   13  1           PH0B4               100 99  102 102 88  95  98  105 100 3           PHP38               100 100 99  100 91  85  101 105 105 3           DIFF               0   2   3   2   3   10  3   0   5   0           PR > T               0.99                   0.00                       0.00                           0.00                               0.43                                   0.03                                       0.00                                           0.99                                               0.48                                                   0.99    __________________________________________________________________________               SOU ECB DRP GLF NLF               RST 25C EAR SPT BLT               ABS ABS % MN                           ABS ABS    __________________________________________________________________________    TOTAL SUM           REPS               1   61  105 5   2           LQCS               1   34  67  5   1           PH0B4               5   5   100 5   3           PHP38               5   5   100 4   4           DIFF               0   0   0   0   2           PR > T               0.99                   0.99                       0.99                           0.99    __________________________________________________________________________     *PR > T values are valid only for comparisons with Locs >= 10.

                                      TABLE 3B    __________________________________________________________________________    Average Inbred By Tester Performance Comparing PH0B4 To PHHB9 Crossed    To The Same Inbred Testers And Grown In The Same Experiments.    __________________________________________________________________________               SEL     BU  BU  PRM     TST SDG EST GDU               IND PRM ACR ACR SHD MST WT  VGR CNT SHD               % MN                   ABS ABS % MN                               ABS % MN                                       ABS % MN                                               % MN                                                   % MN    __________________________________________________________________________    TOTAL SUM           REPS               2   3   16  16  2   18  13  5   12  3           LOCS               2   3   16  16  2   18  13  5   12  3           PH0B4               104 112 156 104 113 96  58  112 103 100           PHHB9               113 112 161 108 113 99  57  103 102 101           DIFF               9   0   4   4   0   4       9   1   1           PR > T               0.19                   0.99                       0.34                           0.28                               0.99                                   0.10                                       0.99                                           0.37                                               0.81                                                   0.20    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN ECH               SLK CNT HT  HT  LDG GRN LDG STK APP 2SC               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN                                                   ABS    __________________________________________________________________________    TOTAL SUM           REPS               1   22  9   9   3   1   12  2   4   2           LOCS               1   21  9   9   2   1   11  2   4   2           PH0B4               104 101 100 99  97  102 95  100 123 4           PHHB9               104 101 101 100 106 119 101 98  89  7           DIFF               0   0   1   1   9   17  6   2   34  3           PR > T               0.99                   0.99                       0.46                           0.47                               0.50    0.25                                           0.00                                               0.06                                                   0.20    __________________________________________________________________________               DRP               EAR               % MN    __________________________________________________________________________    TOTAL SUM           REPS               4           LOCS               4           PH0B4               100           PHHB9               101           DIFF               1           PR > T               0.39    __________________________________________________________________________     *PR > T values are valid only for comparisons with Locs >= 10.

                                      TABLE 3C    __________________________________________________________________________    Average Inbred By Tester Performance Comparing PH0B4 To PHAG6 Crossed    To The Same Inbred Testers And Grown In The Same Experiments.    __________________________________________________________________________               SEL     BU  BU  PRM     TST SDG EST GDU               IND PRM ACR ACR SHD MST WT  VGR CNT SHD               % MN                   ABS ABS % MN                               ABS % MN                                       ABS % MN                                               % MN                                                   % MN    __________________________________________________________________________    TOTAL SUM           REPS               29  58  222 222 44  226 160 58  74  62           LOCS               29  58  222 222 44  226 160 58  74  62           PH0B4               104 112 151 103 110 99  58  102 101 99           PHAG6               102 112 151 103 111 101 57  93  101 100           DIFF               3   1   0   0   1   2   0   10  0   1           PR > T               0.18                   0.02                       0.99                           0.99                               0.01                                   0.00                                       0.99                                           0.00                                               0.99                                                   0.02    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN EYE               SLK CNT HT  HT  LDG GRN LDG STK APP SPT               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN                                                   ABS    __________________________________________________________________________    TOTAL SUM           REPS               24  257 129 122 83  62  192 15  44  1           LOCS               24  251 129 122 77  62  186 15  44  1           PH0B4               100 101 100 99  99  94  100 99  103 4           PHAG6               100 100 99  99  101 94  101 101 94  3           DIFF               0   0   2   1   2   0   0   1   9   1           PR > T               0.99                   0.99                       0.00                           0.32                               0.47                                   0.99                                       0.99                                           0.21                                               0.04    __________________________________________________________________________               SOU ECB DRP GLF               RST 250 EAR SPT               ABS ABS % MN                           ABS    __________________________________________________________________________    TOTAL SUM           REPS               1   36  84  5           LOCS               1   36  84  5           PH0B4               6   4   100 4           PHAG6               6   5   100 4           DIFF               0   1   0   0           PR > T               0.99                   0.07                       0.99                           0.99    __________________________________________________________________________     *PR > T values are valid only for comparisons with Locs >= 10.

                                      TABLE 4A    __________________________________________________________________________    INBREDS IN HYBRID COMBINATION REPORT    VARIETY #1 = PH0B4/PH08A    VARIETY #2 = PHR55/PHP38    __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU               PRM SHD ACR ACR MST WT  VGR CNT SHD               ABS ABS ABS % MN                               % MN                                   ABS % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   112 113 143.5                           107 97  57.3                                       122 103 101           2   113 112 136.7                           102 108 55.5                                       109 98  100           LOCS               3   3   17  17  17  12  28  34  10           REPS               3   3   17  17  17  12  32  39  14           DIFF               2   1   6.8 6   10  1.8 13  5   1           PR > T               .169                   .223                       .137                           .129                               .000#                                   .002#                                       .030+                                           .006#                                               .069*    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN               SLK CNT HT  HT  LDG GRN LDG STK APP               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   101 102 102 104 108 97  101 99  102           2   100 101 99  98  102 109 102 98  98           LOCS               7   54  20  20  4   3   11  8   4           REPS               7   65  20  20  5   3   12  13  4           DIFF               2   1   3   6   6   12  1   1   4           PR > T               .148                   .454                       .008#                           .006#                               .304                                   .195                                       .755                                           .746                                               .761    __________________________________________________________________________               DRP SLF MDM SOU ECB ECB               EAR BLT CPX RST DPE 250               % MN                   ABS ABS ABS ABS ABS    __________________________________________________________________________    TOTAL SUM           1   100 7.0 3.3 6.0 100.0                                   6.0           2   101 5.5 3.3 7.0 100.0                                   5.5           LOCS               5   1   2   1   1   2           REPS               5   2   4   1   1   2           DIFF               0   1.5 0.0 1.0 0.0 0.5           PR > T               .999    .999        .500    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 4B    __________________________________________________________________________    INBREDS IN HYABRID COMBINATION REPORT    VARIETY #1 = PH0B4/PH08A    VARIETY #2 = PHHB9/PHBE2    __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU               PRM SHD ACR ACR MST WT  VGR CNT SHD               ABS ABS ABS % MN                               % MN                                   ABS % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   112 113 144.7                           106 97  57.3                                       122 102 102           2   112 114 145.8                           106 99  55.8                                       105 103 101           LOCS               4   4   21  21  21  12  59  63  23           REPS               4   4   21  21  21  12  70  74  30           DIFF               0   1   1.1 0   1   1.5 17  1   0           PR > T               .999                   .516                       .820                           .999                               .523                                   .000#                                       .000#                                           .427                                               .999    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN               SLK CNT HT  HT  LDG GRN LDG STK APP               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   102 101 102 102 126 82  101 96  102           2   101 103 99  95  91  98  98  97  97           LOCS               13  94  40  40  5   7   13  14  4           REPS               14  118 46  46  6   8   14  20  4           DIFF               1   2   3   7   35  16  3   1   4           PR > T               .047+                   .122                       .000#                           .002#                               .311                                   .046+                                       .493                                           .878                                               .719    __________________________________________________________________________               DRP GLF SLF MDM SOU ECB ECB               EAR SPT BLT CPX RST DPE 2SC               % MN                   ABS ABS ABS ABS ABS ABS    __________________________________________________________________________    TOTAL SUM           1   100 5.0 7.0 3.3 6.0 100.0                                       6.0           2   100 4.0 7.0 4.5 6.0 100.0                                       5.0           LOCS               5   1   1   2   1   1   2           REPS               5   1   2   4   1   1   2           DIFF               0   1.0 0.0 1.3 0.0 0.0 1.0           PR > T               .999        .126        .000#    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 4C    __________________________________________________________________________    INBREDS IN HYBRID COMBINATION REPORT    VARIETY #1 = PH0B4/PH08A    VARIETY #2 = PHP38/PHPP8    __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU               PRM SHD ACR ACR MST WT  VGR CNT SHD               ABS ABS ABS % MN                               % MN                                   ABS % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   112 113 150.5                           108 97  57.6                                       124 103 102           2   112 110 137.5                           98  99  55.5                                       116 101 99           LOCS               4   5   17  17  17  12  37  42  17           REPS               4   5   17  17  17  12  43  51  23           DIFF               0   2   13.0                           10  2   2.1 8   2   3           PR > T               .999                   .002#                       .010+                           .006#                               .191                                   .015+                                       .076*                                           .152                                               .000#    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN               SLK CNT HT  HT  LDG GRN LDG STK APP               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   102 102 103 103 107 97  103 96  102           2   99  101 102 103 102 86  103 108 111           LOCS               8   66  21  21  3   3   13  13  4           REPS               8   88  24  24  4   3   14  19  4           DIFF               3   1   1   0   5   11  0   12  9           PR > T               .075*                   .572                       .361                           .999                               .423                                   .187                                       .999                                           .212                                               .477    __________________________________________________________________________               DRP SLF MDM SOU ECB ECB               EAR BLT CPX RST DPE 250               % MN                   ABS ABS ABS ABS ABS    __________________________________________________________________________    TOTAL SUM           1   100 7.0 3.3 6.0 100.0                                   6.0           2   100 7.0 3.0 6.0 100.0                                   5.0           LOCS               5   1   2   1   1   2           REPS               5   2   4   1   1   2           DIFF               1   0.0 0.3 0.0 0.0 1.0           PR > T               .617    .500        .500    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 4D    __________________________________________________________________________    INBREDS IN HYBRID COMBINATION REPORT    VARIETY #1 = PH0B4/PH08A    VARIETY #2 = PHP38/PHN46    __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU               PRM SHD ACR ACR MST WT  VGR CNT SHD               ABS ABS ABS % MN                               % MN                                   ABS % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   112 113 148.8                           106 98  57.1                                       121 102 102           2   110 111 141.3                           101 92  56.4                                       126 103 100           LOCS               5   5   25  25  25  15  61  67  24           REPS               5   5   25  25  25  15  72  77  31           DIFF               2   1   7.6 5   6   0.7 6   1   1           PR > T               .009#                   .164                       .052*                           .068*                               .000#                                   .054*                                       .069*                                           .350                                               .002#    __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN               SLK CNT HT  HT  LDG GRN LDG STK APP               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   102 101 102 102 126 82  103 96  102           2   100 102 97  100 121 96  102 97  101           LOCS               14  96  42  42  5   7   17  13  4           REPS               15  117 48  48  6   8   18  18  4           DIFF               2   0   5   2   5   14  1   1   1           PR > T               .001#                   .999                       .000#                           .451                               .268                                   .099*                                       .760                                           .912                                               .922    __________________________________________________________________________               DRP GLF MDM SOU ECB ECB               EAR SPT CPX RST DPE 2SC               % MN                   ABS ABS ABS ABS ABS    __________________________________________________________________________    TOTAL SUM           1   100 5.0 3.5 6.0 100.0                                   6.0           2   100 2.0 3.5 6.0 100.0                                   7.5           LOCS               5   1   1   1   1   2           REPS               5   1   2   1   1   2           DIFF               0   3.0 0.0 0.0 0.0 1.5           PR > T               .999                .205    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

                                      TABLE 4E    __________________________________________________________________________    INBREDS IN HYBRID COMBINATION REPORT    VARIETY #1 = PH0B4/PH08A    VARIETY #2 = PHAG6/PH08A    __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU               PRM SHD ACR ACR MST WT  VGR CNT SHD               ABS ABS ABS % MN                               % MN                                   ABS % MN                                           % MN                                               % MN    __________________________________________________________________________    TOTAL SUM           1   113 113 149.8                           100 98  123 101 102 102           2   110 114 137.4                           90  92  78  101 102 102           LOCS               1   3   4   4   4   53  53  19  10           REPS               1   3   4   4   4   62  64  24  10           DIFF               3   0   12.4                           10  6   45  0   0   0           PR > T  .999                       .469                           .426                               .197                                   .000#                                       .999                                           .999                                               .999    __________________________________________________________________________               STK PLT EAR RT  STA STK BRT GLF SLF               CNT HT  HT  LDG GRN LDG STK SPT BLT               % MN                   % MN                       % MN                           % MN                               % MN                                   % MN                                       % MN                                           ABS ABS    __________________________________________________________________________    TOTAL SUM           1   100 102 101 138 71  103 96  5.0 7.0           2   100 99  102 109 42  89  107 4.0 6.5           LOCS               74  28  28  3   4   2   13  1   1           REPS               97  32  32  3   5   2   19  1   2           DIFF               1   3   0   29  29  13  11  1.0 0.5           PR > T               .561                   .004#                       .999                           .406                               .076*                                   .175                                       .282    __________________________________________________________________________               MDM               CPX               ABS    __________________________________________________________________________    TOTAL SUM           1   3.3           2   2.8           LOCS               2           REPS               4           DIFF               0.5           PR > T               .500    __________________________________________________________________________     * = 10% SIG     + = 5% SIG     # = 1% SIG

DEPOSITS

Applicant has made a deposit of at least 2500 seeds of Inbred Maize LinePH0B4 with the Ameyrican Type Culture Collection (ATCC), Manassas, Va.20110 USA, ATCC Deposit No. 209744. The seeds deposited with the ATCC onApr. 6, 1998 were taken from the deposit maintained by Pioneer Hi-BredInternational, Inc., 700 Capital Square, 400 Locust Street, Des Moines,Iowa 50309-2340 since prior to the filing date of this application. Thisdeposit of the Inbred Maize Line PH0B4 will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the effective life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicant has satisfied allthe requirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample. Applicant imposes norestrictions on the availability of the deposited material from theATCC; however, Applicant has no authority to waive any restrictionsimposed by law on the transfer of biological material or itstransportation in commerce. Applicant does not waive any infringement ofits rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.). Applicant has applied for U.S.Plant Variety Protection of PH0B4 under Application No. 9700201.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene modifications and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

What is claimed is:
 1. Seed of maize inbred line designated PH0B4, representative samples having been deposited under ATCC Accession No.
 209744. 2. A maize plant, or parts thereof, having all the physiological and morphological characteristics of inbred line PH0B4, representative seed of said line having been deposited under ATCC Accession No.
 209744. 3. The maize plant of claim 2, wherein said plant is male sterile.
 4. A tissue culture of regenerable cells of a maize plant of inbred line PH0B4, wherein the tissue regenerates plants capable of expressing all the morphological and physiological characteristics of the inbred line PH0B4, representative seed of which have been deposited under ATCC Accession No.
 209744. 5. A tissue culture according to claim 4, the cells or protoplasts being of a tissue selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, silks, flowers, kernels, ears, cobs, husks, and stalks.
 6. A maize plant regenerated from the tissue culture of claim 4, capable of expressing all the morphological and physiological characteristics of inbred line PH0B4, representative seed of which have been deposited under ATCC Accession No.
 209744. 7. A method for producing a first generation (F₁) hybrid maize seed comprising crossing the plant of claim 2 with a different inbred parent maize plant and harvesting the resultant first generation (F₁) hybrid maize seed.
 8. The method of claim 7 wherein inbred maize plant of claim 2 is the female or male parent.
 9. An F₁ hybrid seed produced by crossing the inbred maize plant according to claim 2 with another, different maize plant.
 10. An F₁ hybrid plant, or parts thereof, grown from the seed of claim
 9. 